1. Field of the Invention
The present invention relates to a woven slide fastener stringer including a row of coiled coupling elements of synthetic resin woven integrally into a stringer tape along a longitudinal edge portion thereof.
2. Description of the Prior Art
One type of woven slide fastener stringer is known in which a row of coiled coupling elements of synthetic resin are woven into a woven stringer tape along one longitudinal edge thereof, two core threads and a stuffer cord are received longitudinally in a space defined through the coiled coupling elements. One of the core threads and one leg of each coupling element is secured by weaving to one longitudinal tape edge. The other leg of the coupling element is firmly secured to the longitudinal tape edge by a binding thread design. The design includes a binding weft thread running between a foundation weft thread located outside the stuffer cord and the other core thread and interlaced with binding warp threads disposed between the foundation weft thread and the stuffer cord. Also the other core thread is not underlaid any other thread (see, U.S. Pat. No. 4,383,558).
In the above-mentioned woven slide fastener stringer having coiled coupling elements, the binding weft thread in the binding thread design has loops each underlying the upper and lower core threads in inter-element spaces, and extending over and across upper leg adjacent to the coupling head and over lower legs. The upper legs are sandwiched between the core thread and the binding weft thread. In making or finishing the woven slide fastener stringer into a slide fastener chain, a group of the coiled coupling elements are cut off and then removed from the binding thread design to form an element-free space portion. The element-free space portion is relatively thin, however, it results that the core threads disposed in the coiled coupling elements adjacent to the upper and lower legs come off and the binding warp threads float from the binding thread design. When the slide fastener stringer is finished into a single slide fastener, the binding warp threads slacken from the tape edge, thus deteriorating the appearance of the slide fastener. In addition, when the slide fastener is closed, the slackened warp threads are likely to be caught between coupling elements, thereby hindering smooth operation of the slide fastener. To avoid this difficulty, the slide fastener stringer may be finished into a slide fastener with a cut portion of the coupling elements left in a space portion. However, due to the presence of the coupling elements, the space portion is relatively thick and undesirable in quality.